Certainly at every stage a sincere devotee is dependent upon mercy. Nevertheless, having received that mercy, the devotee should sincerely repent for his past offenses so that he will not commit them again. That is always the aim of the sincere devotee. He does not want to commit offenses again. He voluntarily accepts suffering through sincere repentance, and by this suffering he remembers to avoid that which was the cause of that suffering.
(Collected Letters To My Disciples, Vol 3, Pg 10, 2nd Paragraph)